Sheree Whitfield from "Real Housewives of Atlanta" better have a Schwinn lying around -- because TMZ has learned her precious Aston Martin was seized this weekend ... after she allegedly screwed over a former ally.

The people behind the seizure are Whitfield's former divorce lawyer, who sued the reality star -- and won -- after she stiffed them out of more than $110,000 in legal fees.

A rep for the lawyer tells TMZ they still haven't received the money -- so this weekend, they had the local sheriff's department snatch the car up as payment.

So now Sheree's short one husband ... AND one Aston Martin.

Sheree tells TMZ she thinks the judgment against her is unfair -- but adds, "It's okay, it's a car, I'll get another one."